Floating dry dock



F. R. HARRIS FLOATING DRYDOCK Filed Jan. e, 1942 Sept. 30, 1947 FIGA.

INVENTOR. 52 FREDEP/c R. HARK/s A TTORNEY Patented Sept. 30, 1947 f UNITED sflmsseV PATE-Nr orrlcs ELQATIN'G DRY D065.;

B redgeric` R.. Harris, NewYork, N. Y.

Application-January: 6, 1942', Serialf blo; 4253736' 8- Claims.

This invention relates to floating dry docks.

Onesubject of the invention is to provide a design of building that simplies the construction so that the dock 'can loel put togetherwith lessskilful labor than has heretofore been re-4 quired.

Another object. of the invention is` to provide animproved dry dock construction which isless expensive to build, and. which is especially `suitable for composite docks, constructed partlyof steeland partly of timber. The invention eects a.. substantial saving in the fastenngs required to.l yconstruct the dock, and fastening-s are anr ini-- portant item in the total cost of a dry dock.

In accordance with one featurev of thefinvention timber truss postsare clamped between. steel bottomv and deck stringere and end grain timber compression is directly transferred into the tension truss members through contact plates that simplify the construction. and protect the stringers that constitute the trusschord section proper., Timbersk have a corrosive effect on steel n1 the presence of moisture because of. acidi in the Wood. With this invention the contact plates. or saddles used over the ends of the timber posts` are made heavy enough so that they are. still of, ample strength even if they suffer some corrosion, and. I-beams of standard design are used' as stri'ngers, the anges of the I-beams. being fully protected by the saddles. This invention provides a dry dock construction that is both simple andipractical and' composite constructions have theY ad`- vantage that the steel acts as ballast for the woodl when the dock is submerged. In the conventional timber dock, the ballast amountsl to as much as 28% of the lifting capacityy of the dock, and i's a considerable item of cost.

The-composite dockcan therefore` be of smaller sizeethan a timber doch of the-same-s-hip capacity andV this reduces the dredging required forr the dock slip.

In accordance with one feature of the invention parts of' the dock, such as bulkheads, are con-r structed `remote; from the place of assembly.- of" the. dock, to. eliminate. carpenter fitting during the assembly of the-structure, and. to reduce. the length of time that the dock requires the useof the' launching Waysk and equipment. This, means that more sections of docks caribeV built in a given length of time with the same number of launching Ways, or that fewer-launching'ways; and less equipmentare required to build thesame number of docks. By the expressionV remote from. the placeV of assembly isnmeant some loca,- tion other than the launching; Ways on. which Cl. 114.-45 )y the. dock is; put together and. then slid intoI thel Water.

Qther objects.. features and: advantages of the: invention Iwill appear or be pointed out as the- 5.. specification proceeds.

In the accompanying drawing, forming apart hereof:

Fig. 1= is: an end: vievc of a complete dock made; in accordance with this. invention.

Fig. 2: is: an enlarged', transverse, sectional viewi through one side ofi the. dry dock shown in: l'ig. 1I. Fig. 3: is. an.` enlargedsectional view of theline 3 3* of Fig'. 2;

Fig.. 4 is an enlarged sectional view taken on` 1251; thex line lia-ll: of- Fig. gloeking from left to. right; Fig. 1' showsla'oating dry dock With a pontoon Il" and sidewallslZ.: Thepontoon M has'a round bottom |13, and hasa. deck M. with an'arcuate. crown. Tapered sections canA be used' in place of 2d the round ones.. Blocks. |51 areshown on the deck It.. The end of` the pontoon is indicated'by the. reference. character I B;

Within the' pontoon there. are deck stringers l1 which are structural steel Lbeams; and bottom stringers Hi which. also are structural steel- I- beams; These stringers necessarily include al numberv of bearn'sections connected: together, asf by eld': Welds. I9.,` in the case of' afwide dry dock, and the stringere extend' from one side 20. to the otherside or the pontoon. v

The. dock includes a central longitudinal bulk.. head El? which; is. Water-tight, and a number oit? swa-sh bulkheads. 2r, 2-3: and;- 'M at spaced re-v gions. transversely ofthe pontoon. Each. of the bulkhead's 21"--24' extends the full length of the pontoon and helps to provide longitudinal rigidityI for the dry doch.

The longitudinaslzbnlflrheads 2 l-2zi1 each include plankingr 2B that passes between reinforcementsy such as: upright reinforcement timbersr 2l' a-t both sdeszof the bulkhead. The deck stringers` I1 are located directly above thebottom stringerev l'8 and' thereV are timbers Z1 betweeny the deck and botV tom stringers at the different stations. lengthwise of' the pontoon as indicated in Fig. 31 At several places:A along thel'ength or' the, pontoon there is; a transverse Water-tight bulkhead 29. located betweenv successi-ve deck and bottom stringere.` and one of which is shownn in Fig. 3.

The transverse bulkheadsv 29' include planking 30' located between uprights 3| that are held` in place by wooden. members 32: which extend to.

the-next stri-nger lf'ly or t8; 'li-hef end |16. of the pontoon is shownv in section in: Eig. 3'.. Endyplanking is; fastened. toi uprightl timbers 34 that are on opposite sides of each of the longitudinal bulkheads 2I-24 and similar to the upright timbers 21 except for greater length. There is a wooden deck stringer 35 across the upper ends of the timbers 34, and a wooden bottom stringer36 across the lower end of these timbers 34. The planking of the deck I4 is fastened to the Stringer 35, and the planking of the bottom I3 to the stringer 39.

The deck planking and bottom planking are fastened to the I-beam stringers I1 and I8, respectively, by bolts, preferably carriage bolts 39. Contact plates or saddles 4U are connected to the bottom iianges of the deck stringers I1 and to the top anges of the bottom stringers I 8 by welding. Welds 4I are indicated in Figs. 3 and 4. There is one of these saddles 40 in position to contact with the topand bottom of each of the invention all of the upright timbers are held in y place without the use of fastening elements penelongitudinal bulkheads 2I-24. These saddles 49 are not connected to the longitudinal bulkheads, but slope downward on either side of the bulkheads, and the upright timbers 21 are out away at their corners to fit into the saddle as shown in Fig. 4.

There is a fabric lining 43 coated with some protecting substance, for example, canvas painted with red lead, between the top of each of the timbers 21 and the under side of the saddle 40. Each end portion of the saddle 40 extends into a yoke 45 and is connected with the yoke by a pin 46. The yoke is welded to a rod 41.

The rod 41 from the saddle 40 at the upper end of the bulkhead 23 (Fig. 2) extends downward in the direction of the lower end of the next bulkhead 22 and is joined by a turnbuckle 48 with a rod 49 extending upward from the yoke 45 that connects with one end of the saddle. 49 at the lower end of the bulkhead 22. The yokes 45, rods 49 and turnbuckle 48 constitute a diagonal tension member 50 that holds the bulkhead in position. There are similar diagonal tension members or braces 50 extending from both sides and from both the top and bottom of each of the bulkheads 2I-24, 'but two tension members are used for the diagonal braces that slope downward toward the right in Fig. 2 and only one tension member for the diagonal bracing that slopes upward toward the right. Such a construction obtains a centralized tension even though it is impossible for the braces from opposite directions both to be on the center line of the truss. The saddles 49 have openings for two pins 46 in one end portion and for a single central pin opening in the other end portion.

The method of constructing the dry dock is as follows:

The center bulkhead 2|, the swash bulkheads 22-24, and similar swash bulkheads for the other half of the pontoon; the sections for the transverse bulkheads 29, and the ends I6 of the pontoon, are constructed fiat on the ground, each of these elements of the dock being made up into separate units remote from the place of assembly of the dock.

The bottom stringers I8 are then located in spaced relation, the distance between them being determined by spacing strakes 52. The longitudinal bulkheads 2 I-24 are placed in their proper upright positions on top of the bottom stringers I8. The transverse bulkheads 29 are then secured in postiion. There may be two or more of these transverse bulkheads along the entire length of the pontoon, and each transverse bulkhead is made in sections that lit between the successive longitudinal bulkheads 2I-24. The

trating or passing through them. The tension members 59 are put in place and the turnbuckles 48 are tightened up to give the transverse truss structure the desired rigidity.

The frames of the wing walls I2 are assembled at on the ground and then hoisted into place and clamped to the truss ends. The bottom and deck planking I3, I4 is then bolted to the flanges of the stringers I8 and I1, respectively, by bolts 39. The side planking of the pontoon and wings is spiked to the upright-,s of the frames of the wings I2. The wing deck 55 is then put on and the dock is ready for launching.

The invention eliminates carpenter iitting in the assembly of the dock as all parts are pre-cut, and the deck and bottom planks are drilled in jig for exact bolt fit. The dock of this inventioncan be assembled in less than half the time of a conventional dock, thus affording corresponding economy of launching ways and equipment.

The preferred embodiment of the invention has been described, but changes and modications can be made and some features of the invention used without others.

I claim:

1. A dry dock pontoon including a transverse truss structure that comprises a deck Stringer, a bottom Stringer, upright timbers between said stringers at spaced positions along the length of the stringers, said timbers `having their grain extending upright, saddles in contact with the end grain of the upper and lower end faces of the upright timbers and extending along a part of the length of the upright timbers, said saddles compressing the upright timbers between them, and diagonally extending tension members connecting the upper and lower saddles of successive upright timbers for imparting rigidity to the truss.

2. A floating dry dock comprising a pontoon including a number of spaced apart bulkheads extending lengthwise of the pontoon, each bulkhead including longitudinally-extending planking and vertical timbers in pairs on opposite sides of the planking at spaced positions along the length of the bulkhead, a metal saddle extending across the upper ends of each pair of said timbers, another metal saddle extending under the lower ends of each pair of said timbers, each of said saddles having end portions that extend at an acute angle to the sides of the vertical timbers, each of said saddles having a corrosionresisting material in contact with the timber, tension members extending from the end portions of the upper saddles to the end portions of the lower saddles of the next bulkhead on each side, turnbuckles in the tension members for adjusting the tension rof said members, a metal deck Stringer welded to the corresponding upper saddles of the respective bulkheads, and a metal4 bottom stringer welded tothe corresponding lower saddles of the respective bulkheads.

3. A floating dry dock comprising a pontoon including a number of spaced apart bulkheads extending lengthwise of the pontoon, each bulkhead including longitudinally-extending planking and vertical timbers positioned in pairs on opposite sides of the planking at spaced positions along the length of the bulkhead, a metal saddle extending across the upper ends of each pair of said timbers, another metal saddle extending under the lower ends of each pair of said timbers, each of said saddles having end portions that extend at an acute angle to the sides of the vertical timbers, each of said saddles having a corrosion-resisting material in contact with the timber, braces extending from the end portions of the upper saddles to the end portions of the lower saddles of the next bulkhead on each side, a metal deck stringer welded to the corresponding upper saddles of the respective bulkheads, and a metal bottom stringer welded to the corresponding lower saddles of the respective bulkheads.

4. A floating dry dock comprising a pontoon including a number of spaced apart bulkheads extending lengthwise of the pontoon, each bulkhead including longitudinally-extending planking and vertical timbers positioned in pairs on opposite sides of the planking at spaced positions along the length of the bulkhead, a metal saddle extending across the upper ends of each pair of said timbers, another metal saddle extending under the lower ends of each pair of said timbers, each of said saddles having end portions that extend at an acute angle to the sides of the vertical timbers, tension members extending from the end portions of the upper saddles to the end portions of the lower saddles of the next bulkhead on each side, turnbuckles in the tension members for adjusting the tension of said members, a metal deck stringer welded to the corresponding upper saddles of the respective bulkheads, and a metal bottom stringer welded to the corresponding lower saddles of the respective bulkheads.

5. A floating dry dock comprising a pontoon including a number of spaced apart bulkheads extending lengthwise of the pontoon, each bulkhead including longitudinally-extending planking and vertical timbers in pairs on opposite sides of the planking at spaced positions along the length of the bulkhead, a metal saddle extending across the upper ends of each pair of said timbers, another metal saddle extending under the lower ends of each pair of said timbers, each of said saddles having end portions that extend at an acute angle to the sides of the vertical timbers, braces extending from the end portions of the upper saddles to the end portions of the lower saddles of the next bulkhead on each side,

a metal deck stringer welded to the corresponding upper saddles of the-respective bulkheads, and a metal bottom stringer Welded to the corresponding lower saddles of the respective bulkheads.

6. A loating dry dock pontoon including longitudinally extending bulkheads spaced from one another transversely of the pontoon, and deck stringers above the bulkheads, a saddle connected with the lower side of each deck stringer above each bulkhead and contacting with the top of the bulkhead over the full width thereof, said saddle extending part way down on opposite sides of the bulkhead, corresponding saddles connected with the upper side of each bottom stringer below each bulkhead and contacting with the bottom of the bulkhead over the full width of the bottom, and means clamping the saddles rmly against the tops and bottoms of the bulkheads.

7. A floating dry dock having parallel bulkheads and an additional bulkhead intersecting same, spaced upright reinforcements on both faces 0f said parallel bulkheads adjacent the places of intersection, plates on the ends of said reinforcements and diagonal braces connecting the ends of said plates of one bulkhead with the ends of the plates of the next parallel bulkhead.

8. A composite steel and wood dry dock pontoon including bulkheads, a steel deck stringer extending across the upper ends of the bulkheads, a steel bottom stringer extending across the lower ends of the bulkheads, timber uprights located between the bulkheads and extending from the deck stringer to the bottom stringer with the end grain of said timber uprights compressed between the steel stringers, brackets connected to the stringers, stems extending from the brackets, and recesses in the end faces of the uprights into which the stems of the brackets extend.

FREDERIC R. HARRIS.

REFERENCES CITED The following references are of record in the file of this patent: 

